What does it mean?
U1002 is a Network (CAN bus, module communications) fault code. It indicates: DIS Microphone 1 short .
Symptoms
- Callers report that they cannot hear the driver, or hear only noise
- Voice control and voice dialling refuse to start or immediately fail
- Loud buzz, hum or static on the hands-free channel
- Head unit shows a microphone or hands-free error message
- Bluetooth pairing works but calls are unusable
- No fault in the rest of the audio system, which points at a single circuit rather than the whole module
Likely causes
- Microphone wiring pinched or crushed where it runs through the A-pillar trim, headliner or overhead console
- Internal short in the microphone element itself after moisture or ageing
- Corroded or wet microphone connector, often after a windscreen leak or sunroof drain blockage
- Screened microphone cable damaged so the signal wire touches the shield or body metal
- Trim panel refitted incorrectly after previous work, trapping the cable behind a clip
- Aftermarket hands-free or camera wiring tapped into the microphone circuit
- Faulty microphone input stage inside the head unit
How to fix it
- Confirm the complaint by making a hands-free test call and by trying voice control
- Locate the microphone, usually in the headliner or overhead console, and unplug it
- With the microphone disconnected, check whether the code changes state, which separates a shorted microphone from shorted wiring
- Measure resistance from each microphone wire to ground and between the wires to find the short
- Inspect the cable route along the A-pillar and headliner for pinch points, clips and crushed insulation
- Check the area for water ingress from the windscreen seal or a blocked sunroof drain, and dry the connector
- Repair the damaged cable section with shielded joints, keeping the screen continuous
- Replace the microphone if it tests shorted, and only suspect the head unit input if a known good microphone still sets the code